The present invention relates to the art of geotextile containers of the type for maintaining fill material and more particularly to a method and apparatus for deploying same.
Conventional geotextile tubes, whether woven on a circular loom or formed by joining two or more mill widths of fabric, have a tendency of rolling forward, as well as backward during the process of filling the tube with solid material. This rolling also tends to occur when the filled tube is hit with forceful wave action.
In a typical application an elongated prior art geotextile container may be constructed with a water permeable geotextile fabric. This geotextile fabric can be defined by its Apparent Opening Size (A.O.S.) as it relates to a standard U.S. Sieve (100 A.O.S. material will retain 95% of all material passing through the 100 sieve).
Once a geotextile container has been filled to its capacity or intended capacity, the moisture or liquid that is present in the fill material can be either leached out of the material or evaporated. Should wave action or high tide allow the permeable geotextile container to gain water and form a slurry, the movement of water (hydrostatic pressure) within the container may cause the material that is smaller than 100 sieve to wash out of the container.
The more soil that washes out of the filled container, the more space is created inside the container to allow further movement of the sand or siliceous material within the container. With this movement, abrasion occurs to the filaments or yarns of the container. As this abrasion progresses, holes appear in the fabric that forms the walls of the container and allow the coarser material to destroy the geotextile fabric until most if not all of the fill has escaped.
The problems posed by storms of hurricane force can be attributed to the geotextile container comprised of a single longitudinal structure of fill (sand). The storm surge can cause the geotextile container to roll inward and in effect “walk” up the beach toward land. Once the geotextile container becomes so displaced from its intended position at which it optimally fights erosion of the beach, the possibility of damage to the beach from erosion increases.
The problems posed by rolling containers have been addressed in containers of the type disclosed in U.S. Pat. No. 5,125,767 having two water impermeable internal tubes with water. However, because such containers derive their heft from water, they tend to be less rigid than desirable in resisting movement from the force of wave action. Moreover, the construction of such containers restricts their maximum attainable height. The containers disclosed in U.S. Pat. No. 5,865,564 having two water-filled intercommunicating compartments also suffer from the foregoing deficiencies.